Monday, September 19, 2016

(This entry is a cross-post from my September CCDE newsletter. If you'd like to receive this to your email inbox two weeks prior to posting on my website, please sign up for my newsletter)

Over my years of helping CCDE candidates prepare for their Practical exam I have often been asked for my help in understanding the score report that an unsuccessful attempt yields. It is unfortunate when a candidate receives an unsuccessful result, but it happens often. Cisco's pass rate for Expert level exams (CCIE + CCDE combined) is approximately 15 - 20% per attempt, so more often than not, a candidate will not pass.

Unlike many of Cisco's written exams, the CCDE Practical does not give you a technology-based breakdown of your performance. While it would be great to receive something like this:

OSPF 70%

EIGRP 40%

IS-IS 30%

L3VPN 95%

Security 30%

etc, etc 10%

You will actually receive this:

1.0 Analyze Design Requirements 40%

2.0 Develop Network Designs 50%

3.0 Implement Network Design 60%

4.0 Validate and Optimize Network Design 90%

(These are made-up scores. If they match yours, I promise I wasn't looking at your paper)

So what can we do with this information? It certainly doesn't tell us which Cisco Press book to re-read in preparation for our next exam attempt. How can you build a study plan that gets will get you the crucial points to pass during the next exam date?

First, trust your gut. Your score report is given to you immediately after completion of the exam. The day's scenarios should be relatively fresh in your mind. Which of the technical topics was most challenging for you? Were there any terms or acronyms that were unfamiliar? I'm not ashamed to admit that during my CCDE Practical exam I came across at least one term that I hadn't been exposed to in my studies. This is why you'll see a few oddball acronyms in my training materials, especially during my practice exam.

Make a list of all of the topics, terms and design situations that made you uncomfortable. If it is a large list, so be it! I still haven't met a CCDE who was completely confident in their results before they saw their score report. The exam is designed to put you, the network designer, in uncomfortable spots. After all, doesn't real-world networking require compromise and educated guessing from time-to-time? The difference being that in the real-world we are allowed to use Google to validate our guesses before hitting submit.

So what does my result in each of these categories actually mean?

1.0 Analyze Design Requirements

This section is worth approximately 36% of your exam. The questions that fall into this category are of the style of 'What additional information do you require to develop your design?' Poor scores on this category reflect trouble understanding the scenario, and especially the business constraints presented. I like to think of this category as the one that tests your reading comprehension capabilities. It has been my experience, when working with students, that low scores make it practically impossible to pass the exam, as your core understanding of the scenario is flawed in some way. It is very difficult to determine the right answer to the following sections without proper knowledge of the core documents.

2.0 Develop Network Designs

This section represents the plurality of points on the exam, about 39% of the total points. These questions can be presented in many ways (multiple choice, multiple answer, diagram/hotspot, etc). The core skill tested in this category is the 'Which network design is most appropriate for this scenario?'. If your scores in this section are low, that represents a hole in your technical knowledge. Perhaps you do not understand one or more of the proposed technologies (if selecting the right solution) or the specific technology in the question (for example, where to place the BGP Route Reflector). Poor performance on this question type also makes section 4.0 (Validate and Optimize Network Design) difficult, as you are likely to go down a branch of the exam that does not have any correct answers available.

3.0 Implement Network Design

These are your implementation plan questions. As we discuss in my training, there is a specific strategy that I recommend for this question type. These represent only 13% of the total points on the exam, but with a passing score at or near 80%, every point counts. Fortunately, getting these questions wrong does not usually lead to a bad branching path.

4.0 Validate and Optimize Network Design

Although this section is only worth 12% of the exam points, I consider it the heart of the CCDE program. These are the questions that ask, 'Why did you make the design recommendation in the previous question?' or 'Why is this other proposed design not optimal?' I like to think of this question type as the one that clarifies whether the candidate knew the answer to the Design Recommendation question that came before it, or whether they had a lucky guess. It is very difficult to guess correctly twice in a row!

I hope this article has helped candidates who were unable to pass on their last CCDE Practical attempt. Next month's article will be a technical one, Provider Backbone Bridging (PBB) 101.